Blood Found on all three fecal stool test cards

[Gerbowman]

I'm 52, male, I have IBS, had a colonoscopy four years ago which was normal.

I have had cramps, gas, my stool is not round, more rectrangular looking, sore rear when sitting, constipation  and loose stools. Five or more bowel movements a day
I eat alot of salad and at least one raw onion a day. I only eat once a day, at night. I also eat tomato sauce everyday of the test.
I had a fecal stool test done, which showed blood on all three slides.
Could the raw onions,tomatoes and salad cause a false positive test?
My stools sometimes look a brownish red color, I did notice alittle what appeared to be blood in the middle of my stool.
I have NOT lost any weight and have no problems excersing everyday.
Other then stomach cramps, mostly when sitting, I feel fine.
Please advise what should be done next and what could be my problem.

[Kevin Pho, MD]

Red meat, turnips, and horseradish are typicaly foods that can cause a false positive.  Certainly if these were included in the salad, it may have caused the positive test.  

In any case, any postive blood test over the age of 50 warrants further evaluation.  Although the likelihood of cancer would be less with a negative colonoscopy 4 years ago, it would be prudent to discuss repeating it, to ensure that nothing has grown in the interim.  Another option would be a flexible sigmoidoscopy, which would be a better tolerated procedure.

I would discuss this with a GI referral.

Followup with your personal physician is essential.

This answer is not intended as and does not substitute for medical advice - the information presented is for patient education only. Please see your personal physician for further evaluation of your individual case.

Kevin, M.D.
Medical Weblog:
kevinmd_b

[John1999]

A related discussion, Positive Occult Stool Test was started.